Repairing rotten floor joists

18 Nov 2009
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United Kingdom

One side of my living room floor is sagging and springy i took the floorboards up last night and noticed the joists had partly crumbled away were the sit in the wall. I'm going to cut off rotten piece and splice a new piece of treated timber and place this into joist hangers.

My question is how far past the rotten piece do i remove the wood and how far should the new piece overlap the old.

what do i treat the existing joist with.

Should i still wrap the new spliced joist in dpc before putting into the joist hanger.

Thanks all
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from your description,i think your in for a shock?
you do not normally sister joists like this with out either cutting back to the next sleeper wall or building a sleeper wall under neath the sound timber.
a few pictures would help.
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